When something changes, like an appointment or a planned event that you are looking forward to, you can react in two ways.
One way to react is with disappointment, which is normal.
The alternative reaction is to say that this is the best thing to happen because it is going to lead to a better outcome. My friend and co-author Brian Tracy would call this attitude being an inverse paranoid. Instead of becoming paranoid and upset, you do the opposite because you are confident that everything that happens is leading you to your ideal outcome.